基于碱性离子液体水解以及双水相胶束体系（ATPMS）提取，以超高效液相色谱法（UHPLC）测定水产品中胆固醇的含量，并以分配系数为指标对ATPMS组成进行了优化。称取0.10 g肉糜状水产品，加入0.36 mol·L^-1氢氧化1-丁基-3-甲基咪唑盐（[C₄mim]OH）碱性离子液体1 mL，于90℃加热30 min，冷却后以5 000 r·min^-1转速离心5 min。取全部上清液，加入3 mL由0.5%（质量分数，下同）1-丁基-3-甲基咪唑乙酸盐[C₄mim]Ac离子液体和5.0%（质量分数，下同） Triton X-114组成的ATPMS[介质为柠檬酸-磷酸盐缓冲液（pH 7.0）]，加热至浊点，保持3 min，取出下层相，用甲醇定容至5 mL，涡旋30 s，超声5 min。分取1 mL过0.22 μm滤膜，滤液供UHPLC分析。结果显示：以由0.5% 1-丁基-3-甲基咪唑咪唑盐（[C₄mim]Im）或[C₄mim]Ac和5.0% Triton X-114组成的ATPMS提取胆固醇时，所得分配系数较高；胆固醇的质量浓度在5~200 mg·L^-1内与其对应的峰面积呈线性关系，检出限（3S/N）为7.5 μg·g^-1；由[C₄mim]Ac组成的ATPMS所得的回收率（84.1%~89.9%）略大于由[C₄mim]Im组成的ATPMS的（80.0%~83.9%），且和参考GB 5009.128-2016设置的对照组（催化剂为氢氧化钾，提取剂为甲醇）的接近，3组试验测定值的相对标准偏差（n=5）基本一致，均小于3.0%。

Method for determination of cholesterol in aquatic products was proposed by UHPLC based on alkaline ionic liquid hydrolysis and aqueous two-phase micellar system (ATPMS) extraction, and the composition of ATPMS was optimised in terms of partition coefficient. Minced meat packed aquatic product of 0.10 g was taken and mixed with 0.36 mol·L^-1 hydroxide 1-butyl-3-methylimidazole salt ([C₄mim]OH) alkaline ionic liquid (1 mL), and the mixture was heated at 90 ℃ for 30 min. After cooling and centrifuging at 5 000 r·min^-1 for 5 min, the entire supernatant was taken, 3 mL of ATPMS [citric acid-phosphate buffer (pH 7.0) as media] consisting of 0.5% (mass fraction, the same below) 1-butyl-3-methyl imidazole acetate ([C₄mim]Ac) and 5.0% (mass fraction, the same below) Triton X-114 was added, and the mixture was heated to the cloud point, keeping for 3 min. The lower phase was taken, diluted to 5 mL with methanol, vortexed for 30 s and sonicated for 5 min. An aliquot (1 mL) of the above solution was taken and passed through 0.22 μm filter membrane and the filtrate was used for UHPLC analysis. It was shown by results that the ATPMS consisting of 0.5% [C₄mim]Im or [C₄mim]Ac and 5.0% Triton X-114 gave a high partition coefficient for extraction of cholesterol. Linear relationship between the mass concentration of cholesterol and respective peak area was kept in the range of 5-200 mg·L^-1, with detection limit (3S/N) of 7.5 μg·g^-1; the results (84.1%-89.9%) of recovery obtained from the ATPMS containing [C₄mim]Ac were slightly higher than those (80.0%-83.9%) obtained from the ATPMS containing [C₄mim]Im, and were similar to those obtained from the control group with reference to GB 5009.128-2016 (KOH as catalyst and methanol as extractant). RSDs (n=5) of the determined values of the three groups were basically the same and less than 3.0%.